1. Field of the Invention
The present invention relates to a control apparatus for varying the fuel pressure in the carburetor to control the rate at which auxillary air and fuel vapor is introduced to the intake manifold of an internal combustion engine to thereby increase the efficiency of combustion, to lower fuel consumption, reduce emission, smooth out engine operation, shorten the period during which choking of the engine is required and improve engine performance during start-up and warming thereof.
2. Description of the Prior Art
Numerous efforts have been made to improve the efficiency of internal combustion engines and reduce emission of partially combusted fuel. These efforts have led to proposals contemplating preheating of fuel and vapor introduced to the engine and to controls which increase the introduction of vapor in proportion to the magnitude of partial vacuum sensed in the intake manifold. A device of this type is shown in U.S. Pat. No. 4,334,422 to Mahoney.
Other efforts have led to proposals which provide for introduction of atomized vapor when the engine is loaded (U.S. Pat. No. 1,974,865) and single vapor control valves which totally close during times when additional water is ideally needed for enhanced combustion, U.S. Pat. No. 4,342,288.
Still further efforts have led to the development of fluid injection systems of the type shown in U.S. Pat. Nos. 4,300,483 and 3,865,907.
However, none of the prior art devices known to applicant provide for complete control of the rate at which air and fuel vapor are introduced to the intake manifold over the entire range of engine operation to thereby vary the fuel pressure in the carburetor, smooth out performance and provide economical performance and reduce emission at all stages of operation.